Download IS 6008 (1989): Arc Welding Power Source, Single Operator

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IS 6008 (1989): Arc Welding Power Source, Single Operator
Rectifier Type, ac and dc [ETD 21: Electric Welding
Equipment]
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IS 6008:1989
( Reaffirmed 2004 )
Indian Standard
ARC WELDING POWER SOURCE,
SINGLE OPERATOR RECTIFIER TYPE,
ac AND dc - SPECIFICATION
( First Ne vision )
UDC
621*791’75’03
@I BIS
BUREAU
MANAK
March
1990
OF
BHAVAN.
INDIAN
1990
STANDARDS
9 BAHADUR
SHAH
NEW DELHI 110002
ZAFAR
MARG
Price Group 3
Electric Welding Equipment
Sectional Committee,
ETD 21
FOREWORD
This Indian Standard ( First Revision ) was adopted by the Bureau of Indian Standards on 21
February 1989, after the draft finalized by the Electric Welding Equipment Sectional Committee had
been approved by the Electtotechnical Division Council.
This standard was first published in 1971. In this revision effort has besn made to align the
requirements with IS 4559 : 1986 ‘Specification for single operator rectifier type dc arc welding
power source ( first revision )‘.
This standard deals with ac and dc arc welding power sources incorporating
solid state rectifiers.
Rectifier type arc welding power source could be either with ac and dc output or dc output only.
This standard is intended to cover the former type only, while 1s 4559 : 1986 deals with the latter
type.
In preparing this standard, assistance has been derived from the following:
a) IS0 700-1982 Power sour_ces for manual metal arc welding with covered electrodes and for the
TIG process. International Organization for Standardization (ISO).
b) BS 638 : Part 2 : 1979 Arc-welding
power sources, equipment and accessories, Part 2
Specification for air cooled power sources for manual metal-arc welding with covered electrodes and for TIG welding. British Standards Institution.
c) EW I-1 983 Electric arc-welding power sources.
USA.
National
Electric Manufacturers’
Association,
For the purpose of deciding whether a particular requirement of this standard is complied with, the
final value, observed or calculated, expressing the result of a test or analysis, shall be rounded off in
accordance with IS 2 : 1960 ‘Rules for rounding off numerical values ( revised )‘. The number of
significant places retained in the rounded off value should be the same as that of the specified value
in this standard.
IS 6008 : 1989
Indian Standard
ARCWELDINGPOWERSOURCE,
SINGLEOPERATORRECTIFIERTYPE,
ac AND dc- SPECIFICATION
( First Revision )
1 SCOPE
3 TERMINOLOGY
1.1 This standard lays down the requirements and
tests for single operator ac/dc arc welding power
source incorporating
solid state rectifiers and
having drooping characteristics.
3.0 For the purpose of this standard,
ing definitions shall apply.
1.2 This standard
does not cover ‘constant
potential’ and other special types of rectifier arc
welding power sources.
Metal-arc welding in which the arc length and the
travel of electrodes or the work pieces are
automatically controlled.
2 REFERENCES
2.1
The following Indian Standards are necessary
adjuncts to this standard:
Title
IS No.
IS 1248 ( Part 2 ) : 1983 Specification
for direct
acting indicating analogue electrical measurinstruments
and
ing
their accessories,
Part
2 Ammeters and volt( second revimeters
IS 1271 : 1985
3.1 Automatic
the follow-
Arc Welding
3.2 -Duty Cycle
The ratio of time during which the output side
of the arc welding power sources is loaded, to
the total elapsed time, the primary side being
energized throughout.
3.3 Load Characteristics
The specified relationship between load voltage
and load current of arc welding power source.
3.4 Load Voltagi
sion )
The voltage between the output terminal of the
arc welding power source when a specified
current is flowing.
Thermal evaluation and
classification of electriinsulation
(first
cal
3.5 Manual
Welding )
revision )
IS 2511 : 1963
Specification for lpolycrystalline semi-conductor rectifier stacks
1s 2834 : 1986
Specification for shunt
capacitors
for power
systems ( second revi-
sion )
IS 3895 : 1966
Specification for monocrystalline semi-conductor rectifier cells and
stacks
IS 4559 : 1986
Specification for single
operator
rectifier type
dc arc welding power
source (first revision )
IS 9678 : 1980
Methods of measuring
temperature-rise of electrical equipment
Metal-Arc
Welding
( Hand
Metal arc welding with consumable electrodes not
exceeding 460 mm in length and applied by the
operator without automatic or semi-automatic
means of replacement.
3.6 Maximu-
Continuous
Automatic
Weld-
ing Current
The maximum welding current
which the arc
welding power source is capable of delivering for
continuous operation on automatic
or semiautomatic arc welding at specified load voltage
and duty cycle without exceeding the specified
temperature-rise.
3.7 Maximum
Continuous
Hand
Welding
Current
The maximum welding current which the welding
power source is capable of delivering
when
engaged continuously
for manual
metal-arc
welding, at the specified load voltage and duty
cycle without exceeding the specified temperaturerise.
IS 6008 : -1989
3.8 Maximum
Hand Welding
depending upon whether the power source is designed
Current
for connection
system.
The maximum welding current for which the arc
welding power source is calibrated for manual
metal-arc welding at the specified load voltage.
to two or three
lines of a three phase
4.2 Rated Frequency
The rated frequency shall be 50 Hz.
3.9 Minimum
Automatic
Welding
Current
4.3 Rated Open-Circuit
The minimum welding current for which the
arc
welding power source is calibrated for automatic
or semi-automatic
welding at the specified load
voltage.
3.10 Minimum
Hand Welding
The open-circuit voltage of the arc welding power
source shall not exceed 100 V for ac/dc output.
NOTE-Where it is required to control the open-circuit
voltage for safety purposes, suitable safety devices may
&ltecorporated
Current
.
The minimum welding current for which the arc
Open Circuit
Voltage
high
NOTE - This does not include superimposed
frequency voltage and voltage derived from low voltage
safety device.
150, 200, 300,400,500,
4.4.1 Minimum
3.12 Rating
3.13 Routine Tests
Arc Welding
It shall be a matter
of agreement
purchaser and the supplier.
3.15 Type Tests
4.4.3:Maximum
source
welding
comply
by tests
is sub-
voltage
shalLbe
Hand Welding Current
4.5 Duty Cycle
The rated duty cycle at maximum
continuous
hand welding current shall be taken as 60 percent; the total duration of each cycle shall be 5
minutes comprising a period of 3 minutes of
load followed by a period of 2 minutes of noload operation.
Voltage
input
the
voltage.
..4 RATING
rated
between
The maximum
hand welding
current
shall not
exceed 1’35 times the corresponding
rated ac and
dc currents,
respectively
at the specified load
NOTE - An arc welding power: source is considered
to be representative
of others if it is identical in rating
and construction.
The preferred
Hund Welding Current
4.4.2 Minimum Automatic -Welding Curwnt
Metal-arc welding in which the arc length is
automatically
controlled but the positioning of
the arc is manual.
Input
600, 900 and 1 200 A.
It is intended that name-plate of the welding
transformer shall indicate the current not less
than 20 percent of the rated current but while
checking the conformity of this clause, the tolerance of current indicated in 9.2 should be taken
into account.
Tests carried out on each arc welding power
source to check requirements which are likely to
vary during production.
4.1 Rated
down to the desired
The minimum hand welding current shall be not
more than 20 percent of the rated current both
for ac and dc output at the specified load
voltage.
A statement of operating parameters assigned to
the~arc welding power source by the manufacturer
under specified conditions.
Tests made on an arc welding power
which is representative
of other arc
power sources to demonstrate that they
with specified requirements not covered
to which each individual power source
jected.
voltage
The ac/dc arc welding power source shall be
rated at current-and duty cycles corresponding to
the maximum continuous hand welding current.
Each power source shall, therefore, have two
rated currents, one for ac output and the mother
for dc output.
Preferred output current ratings,
for higher of the two rated currents, shall be:
The voltage between the output terminals of the
arc welding power source when no current is
flowing in the welding circuit.
3.14 Semi-Automatic
to bring
.
4.4 Rated Current
welding power source is calibrated for manual
metal-arc welding at the specified load voltage.
3.11
Voltage
240 V
4.5.1 The rated duty cycle at maximum continuous automatic welding current shall be taken
as 100 percent.
Duty cycles other than 100 percent shall be a matter of agreement between the
purchaser and the supplier.
or 415 V.
NOTE - In case of a rectifier type arc welding power
source suitable for 415 volts, supply should be taken
either from two lines or three lines of three phase supply
2
IS 6008 : 1989
4.5.2 The rated duty
6.7 Frame and Enclosures
cycle at maximum continuous semi-automatic welding shall be a matter
of agreement between the purchaser
and the
supplier.
4.6 Tolerance
on Open Circuit
The permissible tolerance
voltage(s)
shall be f5
limitation given in 4.3.
5 NORMAL
SERVICE
The arc welding power source shall be so manufactured that it has the strength and rigidity
necessary to withstand rough usage. It shall be
provided with an enclosure or tank which shall
enclose all live metal parts other than a flexible
supply cord or cable and output terminals.
Voltage
for the open circuit
percent subject to
6.7.1 The enclosure or tank shall be so constructed as to exclude vertically falling water or dirt.
CONDITIONS
6.7.2 The enclosure of the tank shall be provided
with suitable lifting lugs. In case of oil immersed
power sources, an oil level indicator and a drain
plug shall also be provided.
5.1 Tbis standard applies to ac/dc arc welding
power sources operating
under the following
normal service conditions ( see also 11.8.3 ):
a) Reference ambient temperature
b) Altitude not exceeding
4O”C, and
6.8 Earthing
1 000 m.
Two earthing terminals shall be provided for
two separate and distinct connections to earth of
all metallic parts -which are not intended to carry
current.
Earthing
terminals shall be suitably
protected against corrosion and shall Abe metallically clean. Earthing terminals shall be indelibly
marked with the symbol _*1
6 DESIGN AND CONSTRUCTION
6.1 The rectifier assembly shall be isolated from
the mains supply by a double wound transformer.
,Output terminals shall be insulated from the
<enclosure and shall be suitably protected against
.accidental or inadvertent contact.
-
6.9 Protection
‘6.2 Monocrystalline rectifiers shall be of adequate
current carrying capacity and able to withstand,
with surge devices, if fitted, transient voltages
likely to occur from arc welding and allied
processes. These rectifiers
shall comply
with
IS 3895 : 1966.
7.1
Capacitors may be used to improve
the
power factor to approximately
0.85 lagging at
50 percent of the higher of the two maximum
continuous hand welding currents
and the
specified load voltage ( see Table 1 >.
7.2 The capacitors, if provided as part of the arc
welding power source, shall conform to IS 2834 :
1986.
7.3 The capacitor shall be so connected that it is
switched off with the arc welding power source.
,6.5 The rectifier assembly shall be of adequate
capacity such that its temperature-rise
shall not
exceed the value stipulated
by the rectifier
manufacturer at the rated output.
shall
shatl
7 CAPACITORS
6.4 Where forced draught cooling is used, an
,automatic device which switches off the rectifier
or reduces the output to a safe level in the event
of inadequate airflow, shall be fitted.
source
Corrosion
All metallic parts and surfaces of assembly
be suitably protected against corrosion.
.6.3 Polycrystalline
rectifiers ( metal rectifiers )
shall comply with IS 2511 : 1963, except for the
voltage test, which shall be in accordance
with 11.8 of’ this standard.
6.6 The arc welding power
capable of withstanding:
Against
Table
1 Welding
Welding
Current
( Clauses 7.1, 9.2 and
be
Welding
a) the full specified supply voltage
without
the necessity for reforming the rectifier
cells by the application of reduced voltage,
and
Current
A
b) an ac voltage instantaneously
applied and
maintained for 5 minutes which is 10 percent higher than the voltage appropriate
to the selected primary voltage tapping.
It shall also be able to withstand repeated
switching off the ac supply at the same
excess
voltage when
the dc output
terminals are not connected to an external
,load.
11.5 )
Welding
Load Voltage
V
150
26
200
28
300
32
400
~36
500
600
and
Load Voltage
and above
40
44
NOTE - The above load voltages are based on the
formula U - 20 + 0’04Zwhete CJ is the load voltage
and Z is the load current ; this formula is applicable to
all welding currents up to 600 A.
3
ItibO8
: 1989
8 CONTROL
AND PROTECTIVE
10 MARKING
DEVICES
8.1 If a switch, controller
or circuit breaker is
employed in the rectifier type arc welding power
10.1 The following information
the rating plate:
it shall be suitable
for the particular
source,
application
and shall conform
to the relevant
Indian Standard(s).
a>Manufacturer’s
of all
regulating
8.3 Remote
Control
IS 6008 : 1989;
4 Type and manufacturer’s serial number;
d) Range of welding current ( minimum and
maximum ) : for ac and dc;
continuous
e) Maximum
hand
welding
current : for ac and dc;
taps,
Devices
f) Maximum
continuous automatic
current : for ac and dc;
Remote control devices, if provided, shall not
operate at voltage exceeding 110 V. For the
supply to the control circuits, power shall be
taken from a winding electrically isolated from
the supply mains.
j) Rated input voltage, frequency and number
of phases;
k) Open circuit voltage, minimum and maximum, for ac and de;
m) Type of cooling;
n) Mass;
p) Class of insulation;
q) Country of manufacture; and
r) A warning worded as follows:
9.1 The arc welding power source shall be capmaximum
continuously
able of
operating
continuous hand welding current at the specified
duty cycle ( see 4.5 ) without overheating.
and Accuracy
The arc welding power source shall carry a
means of indicating the load current which takes
into account the relationship between conventional load voltage and conventional welding
current as given in Table 1. The accuracy of
this indication shall be within &lo percent of
the true value unless the maximum output current
exceeds ten times the minimum output current.
In this case, the accuracy at minimum current
shall be:
f
%I,
I-
welding
g) Duty cycle at maximum current;
h) Input current at rated output at 60 percent
duty : for ac and dc;
9 PERFORMANCE
9.2 Indication
name )r trade-mark;
b) Reference to Indian Standard, that is, Ref
if provided,
shall be such as to make positive contact between
moving and stationary contacts.
Visual indicator shall be provided to indicate the current
setting.
8.2 Contacts
shall be given on
WARNING : Currents in excess of
following are for intermittent use only:
For hand welding
. . . Amperes
For automatic welding
. . . Amperes
the
10.2 The ac and dc arc welding power sources
shall be fitted with two current calibration charts,
for ac and dc output.
percent
Min
10.3 The polarity of the output terminals meant
for dc shall be marked in relation to polarity in
the following manner:
and the accuracy at maximum current shall be
& 10 percent, with the accuracy varying linearly
between these two values.
a) Positive terminals as ‘-I-‘, and
Whatever the method of regulation, the difference
between the indicated currents corresponding to
two succesive positions of the setting device
shall in no case exceed 15 percent of the higher
of the two indicated currents.
b) Negative terminals as ‘-‘.
In case a polarity changeover switch is provided,
the polarities marked are for straight connections
only.
NOTES
I Subject to agreement between the purchaser and
the manufacturer,
scales graduated to indicate the
current under other than conventional
load voltages
may be fitted for specificpurposes.
11 TESTS
2 In exceptional cases where because of the design of
the welding equipment ( for example, devices with dual
control ) it is impracticable 10 obtain a graduated scale
for currents for conventional load voltage, it is recommended that the manufacturer
provides on the equipment an ammeter
of class index 2.5 [see IS 1248
(Part 2 ) : 1983 1, properly damped to indicate
the
welding current.
Tests shall be carried out to prove compliance
with all the requirements of this standard.
11.1 Type Tests
11.1.1 These tests may be carried out by mutual
agreement between the purchaser and the supplier
and if the records of type tests on arc welding
power source which, in essential detail, is
4
the dc output terminals are not connected
external load.
representative
of the one being purchased are
furnished, the purchaser
may accept these as
evidence of ‘type tests’ ( see 3.15 ) instead of
actual tests. Type tests and their sequence shall
be as follows:
a)
b)
c)
d)
11.5 Open-Circuit
circuit voltage
dc output.
11.7 Short-Circuit
Test
Test
Steady short-circuit current at maximum setting
within the range specified shall be not more than
200 percent of the welding current corresponding
to this setting. Under short-circuit conditions,
the voltage between output terminals shall not
exceed 3 volts.
shall be as
a) Insulation resistance test ( 11.3 ),
b) Open-circuit voltage test ( 11.5 ),
c) Load characteristics test ( 11.6 ),
NOTE - Care shall be taken to ensure
does not take more than 10 seconds.
11.8 Temperature-Rise
l1.8.1
( repeated )
that
this
test
Test
Test Conditions
11.8.1.1 The load should be a non-inductive
resistance at the appropriate
load voltage. A
tolerance of f10 percent shall be allowed on
the value on this load voltage.
61.2.1 A certificate of routine
tests shall be
furnished by the manufacturer which shall show
that each of the arc welding power source had
been subjected to the tests specified in 11.2 and
that it complies with the requirements specified in
this standard for these tests and that each of the
arc welding power source has been found to be
sound electrically and mechanically and is in
working order in all particulars.
Resistance
for both ac and
For the purpose of this test, the input side of the
arc welding power source shall be connected to
rated input voltage and the output terminals shall
be connected to a variable resistive load. The
associated load currents and load voltages shall
be as given in Table 1.
Short-circuit test ( 11.7 ),
Temperature-rise
test ( 11.8 ),
High voltage test ( 11.9 ), and
resistance
test
Insulation
( repeated )
( 11.3 ).
11.2 Routine Tests
I I.3 Insulation
shall be measured
11.6 Load Characteristic
e)
f)
g)
h)
d) Short-circuit test ( 11.7 ),
e) High voltage test ( 11.9 ),
resistance
test
f) Insulation
( 11.3 ).
Test
With the input side connected to the rated input
voltage and output side open-circuited, the open-
Insulation resistance test ( 11.3 ),
Over voltage test ( 11.4 ),
Open-circuit voltage test ( 11.5 ),
Load characteristics test ( 11.6 ),
The routine tests and their sequence
follows:
Voltage
to an
11.8.1.2 Test
voltage.
shall be made at the rated input
11.8.1.3 Arc welding power sources suitable for
hand welding shall be tested for temperature-rise
at a current equal to the maximum
continuous
hand welding current and at the duty cycle equal
to 60 percent, for ac and dc output.
Test
For the purpose of this test, the rectifier cells
shall be short-circuited on both the ac and dc
sides while remaining connected to the transformer.
Protective or filter devices or capacitors
shall be disconnected
or short-circuited
as
desired.
11.8.1.4 Arc welding power sources suitable for
both semi-automatic and automatic welding shall
be tested for temperature-rise at a current equal
to the maximum continuous automatic welding
current and at a duty cy,clc equal to 100 percent,
for ac and dc output.
11.3.1 The insulation resistance before and after
high voltage test shall be not less than 2 megohms. The insulation resistance shall be measured
with dc voltage of about 500 V applied for a
sufficient time for the reading of the indicator to
become practically steady, such voltage being
taken from an independent source or generated
in the measuring instrument.
11.8.1.5 The temperature-rise
test shall continue
until steady maximum temperature
is obtained.
If the temperature-rise
does not vary by more
than 20°C per hour, it is considered that steady
temperature has been achieved.
11.4 Over Voltage
11.8.2 When
measured
in accordance
with
IS 9678 : 1980, the temperature-rise
shall not
exceed the limits specified in Table 2.
Test
11.8.3 For ambient temperature exceeding 40°C
or altitude more than 1 000 m or both, the derating factor shall be subject to agreement between
the purchaser and the supplier.
An over voltage test shall be made as specified
in 6.6 followed by repeated switching
off the ac
supply,
50 times, at the same excess voltage when
5
IS 600%: 1989
11.9 High Voltage Test
c) For all auxiliary circuits, not exceeding
110 volts to earth - 1 000 volts.
For the purpose of this test, the rectifier cells
shall be short-circuited on either or both the ac
and dc sides while remaining connected to the
transformer.
hall
NOTE - Protective or filter devices or capacitors
be disconnected or short-circuited
as desired.
11.9.1 As type test, this test shall be applied
the conclusion of the temperature-rise test.
11.9.2 The
alternating
wave form
between 40
at
test shall be made with a single-phase
voltage as nearly as Fossible of sineand of any convenient
frequency
and 60 Hz.
11.9.3 The rms or peak value of the applied
voltage shall be measured.
The rms value shall
be as follows:
a) For the transformer alone when tested
prior to inclusion in the complete unit 2 000 volts;
b) For the complete unit except as for (c)
below 1 500 volts; and
Table 2 Limits
11.9.4 The appropriate voltage, obtained from a
separate source, shall be applied for 60 seconds.
to each winding in turn, between the winding
under test and the remaining windings, core,
frame and tank or casing of the transformer,
connected together and to earth.
11.9.5 The test shall be commenced at a voltage
not greater than one-third of the test value, and
shall be increased to the specified value as rapidly
as is consistent, with its magnit? de being indiAt the end
zated by the measuring instrume
of the test, the voltage shall be r. Juced rapidly
to less than one-third of its full value before
switching off.
NOTE -This
test should not be carried out when
insulation resistance value is below 2 megohms,
the
11.9.6 If this test is required to be repeated, the
test voltage levels shall be reduced to 75 percent
of the original values.
of Permissible
Temperature-Rise
t, Clause 11.8.2 )
-
-
Temperature
Part of
Machine
Sl
No.
in “C (See Note
1)
Class of Insulation
A
E
F
B
T
R
T
R
T
R
T
55
60
65
75
70
80
85
-
-
-
-
-
_
1
Insulated
2
Oil
50
3
Uninsulated
pacts
including cores not
in contact with insulated winding
The temperature-rise
shall in no
injury to any insulating material
source in any respect.
windings
Rise
H
R
T
R
100
105
125
-
-
_
case reach such a value that there is risk of
on adjacent parts or to the welding power
NOTES
1 Method of temperature measurement, by thermometer
(T), by resistance (R).
2 The numerical values quoted for Class F and H insulation should be considered
as tentative
only and may be
revised when more practical experience is available.
If ClassC insulation is used, the temperature-rise
shall be
a matter of agreement between the purchaser and the supplier.
3 For details of classes of insulation, see IS 1271 : 1985.
~
6
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the Bureau of Indian Standards.
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Revision
of Indian Standards
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Users of Indian Standards should ascertain that they are in possession
are issued from time to time.
Comments on this Indian Standard may be sent to BIS giving
of the latest amendments or edition.
the following reference :
Dot : No. ETDC 21 ( 2819 )
Amendments
Issued Since Publication
Date of Issue
Amend No.
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